What is the role of L carnitine (Levocarnitine) in patients with Chronic Kidney Disease (CKD)? Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get History of L carnitine: Implications for renal disease Journal of Renal Nutrition If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy.